And ester hydrolysis

The antibacterial agent nalidixic acid [389-08-2] (37) is formed by reaction of 2-ainino-6-methylpyridine [1824-81 -3] with an alkoxymethylenemalonic ester to form the 1,8-naphthyridine carboxyUc ester followed by alkylation and ester hydrolysis (37). 

Countercurrent flow has advantages in product and thermodynamically limited reactions. Catalytic packings (see Figure 9. Id) are commonly used in that mode of operation in catalytic distillation. Esterification (methyl acetate, ethyl acetate, and butyl acetate), acetalization, etherification (MTBE), and ester hydrolysis (methyl acetate) were implemented on an industrial scale. 

Steric hindrances may also be the reason why quaternary salts of 8-alkylnarcotoline (130) were transformed during Hofmann degradation to analogous keto acids (131) (111,112) and not to the enol lactones (Scheme 24). In some cases (5,87) the keto acids and their esters have been synthesized from the corresponding enol lactones by hydration (Section III,A,2). Nornarceine (107) was prepared from JV-benzyl-(—)-a-narcotinium bromide (139, X = Br) by Hofmann degradation followed by N-debenzylation and ester hydrolysis (109). 

That this difference is not due to differing electron availability at the nitrogen atom in the two cases is confirmed by the fact that the two amines differ very little in their strengths as bases (cf p. 72) the uptake of a proton constituting very much less of a steric obstacle than the uptake of the relatively bulky BMe3. Esterification and ester hydrolysis are other reactions particularly susceptible to steric inhibition (cf. p. 241). 

Hydrolysis of epoxides and arene oxides Hydrolysis of amides and esters Hydrolysis of glycosides... 

The role of the serine residue in hydrolysis was further examined using pseudo-substrates, e.g. p-nitrophenylacetate—substrates which were only very slowly utilized by the enzyme. The p-nitrophenyl group was slowly released and the acyl group became attached to the same serine in hydrolases which had been detected by DIPF (Kilby and Youatt, 1954). Mechanisms for peptide and ester hydrolysis were therefore proposed in which the acyl group became transiently and covalently bound to serines in catalytic sites (see Hartley et al. 1969). 

Fig. 3.15. Schematic mechanism of CO2 hydration (Steps a-d) and ester hydrolysis (Steps...

E. E. Blatter, D. P. Abriola, R. Pietruszko, Aldehyde Dehydrogenase. Covalent Intermediate in Aldehyde Dehydrogenation and Ester Hydrolysis , Biochem. J. 1992, 282, 353-360. 

The diffusion of the large sucrose molecule may be so slow that a large proportion of the sulphonic acid groups inside the polymer become inaccessible and cannot participate in the reaction [506,508], as was also assumed for esterification (p. 361) and ester hydrolysis (p. 377). 

---